Bath tub board



FIG. 1 is a top front view of a bath tub board showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a right side elevational view thereof; the left side elevational view being a mirror image; and,

FIG. 5 is a front elevational view thereof the rear elevational view being a mirror image. 

The ornamental design for a bath tub board, as shown and described. 